Comparison of different methods for extracting Brucella DNA from anticoagulant cultured in blood culture bottle

  Objective   To compare the effects of different extraction methods of Brucella DNA in anticoagulant cultured in blood culture.

  Methods   In this study, the quantitatively detected inactivated Brucella spp./genomic DNA gradient was added to the blood culture bottle containing anticoagulant. Then different methods were used to extract Brucella DNA. Finally, the real time PCR was used to detect the content.

  Results   The results showed that the magnetic nanoparticles and lysis method could detect the inactivated bacterial solution added with 10² CFU/mL and 10^-3 ng/μL genomic DNA. The centrifugal column method could not detect the inactivated bacterial solution added with 10⁶ CFU/mL and 10 ng/μL genomic DNA without treatment of erythrocyte lysate. Only 10⁴ CFU/mL inactivated bacterial solution and 1 ng/μL genomic DNA were detected after treatment with erythrocyte lysate.

  Conclusion   The treatment of samples with erythrocyte lysate could increase the extraction amount of DNA. Among these methods, the extraction effect of lysis method was best, followed by magnetic nanoparticles method and centrifugal column method. This study provided a method as reference for the Brucella DNA extraction of blood cultures of suspected brucellosis samples, and also provided a new insight for improving the diagnosis rate of brucellosis.